<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../../js/jquery-1.4.2.js"></script>
</head>
<body>
    <div id="div1">
        这是一个div
    </div>
    <button id="b1">
        点我一下
    </button>
</body>
    <script>
        $(function (){
            $("#b1").click(function (){
                $("#div1").html()
            })
        })
    </script>
</html>